Method of Separating Plate Material

ABSTRACT

A method which is capable of completely separating a plate member with a large area without using a peeling member and eliminating a possibility of permanent deformation on the plate member. A plurality of suction pads are suckingly disposed on a surface of a topmost plate member in a substantially lattice shape. Then, while the topmost plate member is held by the suction pads disposed in a zigzag shape among the suction pads disposed in the substantially lattice shape, the topmost plate member is lifted by the remaining suction pads. Finally, the suction pads holding the topmost plate member are lifted.

TECHNICAL FIELD

The present invention relates to a method of separating a topmost plate member from laminated plate members.

BACKGROUND ART

In pressing process, a topmost plate member is separated from laminated plate members to be supplied to a press forming machine. It is general to separate the plate members by lifting the top most plate member by a suction pad. However, the laminated plate members are coated with an oil having a high viscosity of a lubricant, a rust preventing oil or the like and are brought into close contact with each other by their own weight, and therefore, it is difficult to completely separate the plate members by such a method and there is a case of simultaneously lifting up a plurality of sheets of plate members. When the plurality of sheets of plate members are taken, the plurality of sheets of plate members are simultaneously supplied to the press forming machine and there is a concern of destructing a die.

Hence, a method of separating plate members as shown by FIG. 14 is adopted. According to the method, there are used a plurality of pieces of air cylinders 50 each attached with a suction pad 51 at a front end of an output rod 50 a. First, the suction pads 51 are arranged substantially in a lattice shape to be adsorbed onto a surface of a laminated topmost plate member W. Next, while pressing the topmost plate member W by the suction pad 51 on a center side of the plate member W, the topmost plate member W is lifted by the remaining suction pad 51. Then, both side edges of the topmost plate member W are rolled up. In the drawing, the air cylinder 50 to be contracted is painted in gray color. Finally, the topmost plate member W is separated by lifting the suction pad 51 on the center side. A method similar thereto is described in Patent Reference 1.

Further, in order to completely separate the plate member W, there is a case of also using the following method. That is, an oil film between the plate members W is removed by lifting the suction pad 51 while blowing air to a gap between the plate members W from a pipe 52. Further, by engaging an end edge of the lifted plate member W by an exfoliating member 53, the plate member W is elastically deformed to promote to separate the plate member W.

Further, there is also proposed a method of forming a gap between plate members by laminating the plate members provided with recesses and projections and lifting the topmost plate member by a suction pad while blowing air from the gap (Patent Reference 2).

Patent Reference 1: JP-A-06-263275 Patent Reference 2: JP-A-04-39225 DISCLOSURE OF THE INVENTION Problems that the Invention is to Solve

However, in the former method, when an area of the plate member W is enlarged, the plate member W is incompletely separated and a plurality of sheets of the plate member W are liable to be taken. This is because when the suction pads 51 on the both sides are lifted, only a peripheral edge portion of the topmost plate member W is lifted by the suction pads 51, and therefore, when the area of the plate member W is enlarged, a hermetically attached area of the topmost plate member W (an area of a portion of the topmost plate member W pressed to a second plate member by the suction pad 51 on the center side) is enlarged, and a force of sucking the top most plate member W is increased. Further, although there is conceivable a method of increasing an amount of rolling up by the suction pads 51 on the both sides by increasing a stroke of the air cylinder 50, the apparatus is large-sized and is not practical.

Further, when the exfoliating member 53 is used, the surface of the plate member W is liable to be damaged, cut chips of the plate member W are adhered to other plate member by the oil to cause to bring about a failed product.

On the other hand, according to the latter method, although the plate member is firmly separated, the plate members are laminated in a bent state, and therefore, a permanent set is produced at the plate member and there is a concern of pressing the plate member under the state.

In view of such a situation, it is an object of the invention to provide a method of separating a plate member capable of completely separating a plate member having a large area and without a concern of bringing about a permanent set at the plate member even when an exfoliating member is not used.

Means for solving the Problems

A first aspect of the invention for resolving the above-described problem is characterized in a method of separating a topmost plate member from laminated plate members, the method comprising a first step of arranging a plurality of adsorbing devices substantially in a lattice shape to be adsorbed to a surface of a topmost plate member, a second step in which while holding the topmost plate member by the adsorbing devices substantially in the lattice shape which are arranged in a zigzag shape, the topmost plate member is lifted by remaining ones of the adsorbing devices, and a third step of lifting the adsorbing devices holding the topmost plate member at the second step.

According to such a constitution, when the adsorbing devices lifts a peripheral edge portion of the topmost plate member, an air gap formed between the topmost plate member and the second plate member is progressed to a center of the plate member to make other adsorbing devices enable to lift the plate member at the second step. That is, the topmost plate member is lifted by the adsorbing devices arranged substantially in the lattice shape which are arranged in the zigzag shape to be deformed into a wavy shape.

As a result, lifted portions are produced not only at the peripheral edge portion of the plate member but also at the center portion of the plate member and a hermetically attached area of the topmost plate member is reduced. That is, a force of adsorbing the topmost plate member is reduced by that amount, and therefore, a force of lifting the plate member by remaining ones of the adsorbing devices is made to be small and the topmost plate member is completely separated at the third step.

It is preferable that in the second and the third steps, the plate member is lifted by the adsorbing devices by blowing warm wind to between the topmost plate member and a second one of the plate member.

According to such a constitution, the warm wind is blown to a gap between the topmost plate member and the second plate member, a dynamic viscosity of an oil film is reduced, the oil film is made to be easy to be removed, and therefore, the force of adsorbing the topmost plate member is reduced to promote to separate the plate member.

It is preferable that previously, a first inclined face continuous to a lower face from an end face of the plate member is formed at a corner portion on a lower side, and a second inclined face continuous to an upper face from the end face of the plate member is formed at a corner portion on an upper side.

According to such a constitution, the warm wind flows to the air gap between the first inclined face of the upper side plate member and the upper face of the lower side plate member, the warm wind invades the gap between the plate members therefrom, and therefore, the plate members are further firmly separated.

A second aspect of the invention for resolving the above-described problem is characterized in a method of separating a topmost one from laminated plate members, the method comprising a first step of forming a first inclined face continuous to a lower face from an end face of a plate member at a corner portion on a lower side and forming a second inclined face continuous to an upper face from the end face of the plate member at a corner portion on an upper side, a second step of arranging adsorbing devices to be adsorbed to a center portion and both end portions of the topmost plate member, a third step in which warm wind is blown to the end face of the plate member and while holding the topmost plate member by the adsorbing devices arranged at the center portion of the plate member, the topmost plate member is lifted by remaining ones of the adsorbing devices, and a fourth step of lifting the adsorbing devices holding the topmost plate member at the third step while blowing the warm wind to the end face of the plate member.

According to such a constitution, the warm wind blown to the end face of the plate member invades an air gap between the first inclined face of the upper side plate member and the upper face of the lower side plate member and is going to lift the end portion of the upper side plate member. Further, the warm wind flows to an upper side along the second inclined face of the lower side plate member, impinges on the first inclined face of the upper side plate member and is going to lift the end portion of the upper side plate member. Further, when the both end portions of the topmost plate member are rolled up by the adsorbing devices, the warm wind invades the gap between the plate members therefrom and the gap is going to be enlarged. That is, the topmost plate member is lifted in a state of reducing the hermetically attached area of the plate member.

ADVANTAGE OF THE INVENTION

According to the first aspect of the invention, at the second step, the lifted portions of the topmost plate member are produced not only at the peripheral edge portion but also at the center portion, and the area of hermetically attaching the topmost plate member and the second plate member is reduced, and therefore, even when an area of the plate member is large, only the topmost plate member can firmly be separated without using an exfoliating member.

According to a second aspect of the invention, the warm wind is made to be easy to advance to the gap between the plate members, and therefore, the topmost plate member is lifted in a state of reducing the hermetically attached area of the plate member and the plate members are firmly separated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view for explaining a first step of the invention.

FIG. 2 is a view showing an arrangement of a suction pad and a guide member relative to a work.

FIG. 3 is a view showing a state of positioning the work by the guide member.

FIG. 4 is a perspective view of the guide member.

FIG. 5 is a view for explaining a second step of the invention.

FIG. 6 is a view for explaining a third step of the invention.

FIG. 7 is a view for explaining removal of an oil film by blowing warm wind.

FIG. 8 is a view for explaining a principle of separating plate members at a second step.

FIG. 9 is a view for explaining an adsorbing force brought about in a plate member.

FIG. 10 is a diagram showing a relationship between a dynamic viscosity of an oil film and a temperature.

FIG. 11 is a view enlarging to show an end portion of the work.

FIG. 12 is a view enlarging to show end portions of works laminated by two sheets.

FIG. 13 is a view for explaining a force of air operated to the work.

FIG. 14 is a view for explaining a background art method.

DESCRIPTION OF THE REFERENCE NUMERALS AND SIGNS

-   1 . . . air cylinder -   2 . . . output rod -   3 . . . suction pad -   4 . . . guide member -   5 . . . warm wind injecting device -   7 . . . first inclined face -   8 . . . second inclined face -   9 . . . gap

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the invention will be explained in details in reference to the attached drawings as follows.

FIG. 1 through FIG. 4 shows an apparatus used for carrying out the invention.

In the drawings, numeral 1 designates an air cylinder and a front end of an output rod 2 thereof is provided with a suction pad 3 as adsorbing device. The air cylinders 1 are attached to a carrying device (not illustrated) substantially in a lattice shape by making the output rods 2 vertical. Further, the carrying device is constituted movably in a horizontal and a vertical direction.

A plurality of guide members 4 are arranged at a surrounding of laminated plate members W. As shown by FIG. 4, the guide member 4 is provided with a guide face 4 a brought into contact with end edges of the plate members W, and an upper side of the guide face 4 a is arranged with a warm wind injecting device 5 constituted by arranging a number of nozzles in an up and down direction. The guide face 4 a is bent, and therefore, brought into line contact with the end edges of the plate members W to be able to deal with various shapes of the plate members W. The guide members 4 are arranged to be confined to substantially centers among respective suction pads 3 in a longitudinal direction and a transverse direction of the plate members W (refer to FIG. 2). Further, in FIG. 1, only one of the guide members 4 is illustrated and illustration of remaining ones is omitted. The warm wind injecting device 5 is made to be offset from the guide face 4 a by a distance L in order to improve an efficiency of blowing air to the plate members W. (refer to FIG. 3).

Next, an explanation will be given of a method of separating the plate members W by using the apparatus.

Previously, as shown by FIG. 3, the plate members W are laminated above a lifter 6, and the plate members W are positioned by pressing the guide faces 4 a of the guide members 4 to end faces thereof. Further, the plate members W are lifted by the lifter 6 and warm wind is blown from the warm wind injecting device 5 to the end faces of the plate members W on an upper side. Further, at each time of removing the topmost plate member W, the plate members W are lifted by the lifter 6 and the warm wind is blown to the end faces of the plate members W on the upper side.

First, at a first step, the carrying device is moved to right above the laminated plate members W, the air cylinder 1 are expanded and the suction pads 3 are arranged substantially in the lattice shape to be adsorbed to a surface of the topmost plate member W₁ (refer to FIG. 1). That is, the suction pads are arranged on the surface of the topmost plate member W₁ in a state of being aligned both in the longitudinal and the transverse directions.

At a second step shown in FIG. 5, the plurality of air cylinders 1 are contracted while blowing the warm wind to the end faces of the plate members W from the warm wind injecting device 5. Here, while holding the topmost plate member W₁ by the suction pads 3 arranged substantially in the lattice shape which are arranged in a zigzag shape, the topmost plate member W₁ is lifted by remaining ones of the sucking devices 3. In the drawing, the air cylinder 1 to be contracted is painted in gray color.

At a third step shown in FIG. 6, while blowing the warm wind to the end faces of the plate members W from the warm wind injecting device 5, the suction pads 3 for holding the topmost plate member W₁ at the second step are lifted. As a result, the topmost plate member W₁ is lifted by a stroke L of the air cylinder 1 and is separated from a second plate member W₂. The separated topmost plate member W₁ is supplied to a press by the carrying device.

Meanwhile, when a peripheral edge portion of the topmost plate member W₁ is lifted by the suction pads 3 at the second step, an air gap formed between the first plate member W₁ and the second plate member W₂ is progressed to the center of the plate member W₁ and the plate member W₁ is made to be able to be lifted by the other suction pads 3. That is, the topmost plate member W₁ is lifted and deformed in a wavy shape by the suction pads 3 arranged substantially in the lattice shape which are arranged in the zigzag shape. At that occasion, even when the second plate member W₂ is simultaneously lifted as shown by FIG. 8, the second plate member W₂ is separated from the topmost plate member W₁ by an elastic recovery force f.

As a result, there are brought about lifted portions not only at the peripheral edge portion of the plate member W₁ but also at the center portion of the plate member W₁, and a hermetically attached area of the topmost plate member W₁ is reduced. That is, a suction force of the topmost plate member W₁ is reduced by that amount, and therefore, at the third step, a force of lifting the plate member W₁ by the remaining suction pads 3 is made to be small, and the topmost plate member W₁ is completely separated. As a result, even when the area of the plate members W is large, only the topmost plate member W₁ can firmly be separated without using an exfoliating member.

Further, at the second and the third steps, the plate member W₁ is lifted by the suction pads 3 while blowing the warm wind from the warm wind injecting device 5 to the gap between the topmost plate member W₁ and the second plate member W₂, and therefore, as show by FIG. 9, the warm wind is blown to the gap between the plate members W₁, W₂, a dynamic viscosity of an oil film o is reduced and the oil film o is made to be easy to be removed. Therefore, an adsorbing force F of the topmost plate member W₁ is reduced to promote to separate the plate member W₁. FIG. 9 is a view for explaining a state of producing the suction force F at the plate members W by a surface tension Fp of the oil film o. FIG. 10 is a diagram showing a relationship between the dynamic viscosity of the oil film and a temperature.

Meanwhile, it is preferable to provide an inclined face as shown by FIG. 11. That is, a first inclined face 7 continuous to a lower face Wa from the end face of the plate member W is formed at a corner portion on a lower side, and a second inclined face 8 continuous to an upper face Wb from an upper end P of the first inclined face 7 is formed at a corner portion on an upper side. The inclined faces 7, 8 may be formed by cutting the upper and the lower corner portions of the plate member W, or may be formed by compressing the end portion of the plate member W. When the plate member W is a soft material such as aluminum, the first and the second inclined faces 7, 8 may be formed by compression.

When the inclined faces 7, 8 are provided, the warm wind horizontally injected from the warm wind injecting device 5 invades an air gap 9 between the first inclined face 7 of the upper side plate member W₁ and the upper face Wa of the lower side plate member W₂ and is going to lift the end portion of the upper side plate member W₁ (refer to FIG. 13). Further, the warm wind flows to an upper side along the second inclined face 8 of the lower side plate member W₂, impinges on the first inclined face 7 of the upper side plate member W₁ and is going to lift the end portion of the upper side plate member W₁. That is, the end portion of the upper side plate member W₁ is operated with a lift up force F by the warm wind. Further, when the end portion of the topmost plate member W₁ is rolled up by the suction pads 3, the warm wind invades the gap between the plate members therefrom and the gap is enlarged. That is, the topmost plate member W₁ is lifted in a state of reducing the hermetically attaching area of the plate member. Therefore, even when the background art separating method shown in FIG. 14 is adopted, the plate members can be separated, there is no hazard practically.

In order to increase the force F of lifting up the end portion of the plate member, it is preferable to form the first and the second inclined faces 7, 8 as follows. That is, it is preferable to form the first inclined face 7 such that a rate of a height h as compared with a wall thickness t of the plate member W is 15 through 25%. It is preferable to form an angle of inclination α of the first inclined face 7 to be 10 through 20 degrees, and an angle of inclination β of the second inclined face 8 to be 10 through 20 degrees, that is, form an angle γ made by the first and the second inclined faces 7, 8 to be 80 through 100 degrees. As a result, an angle δ made by the first and the second inclined faces 7, 8 becomes 80 through 100 degrees between the contiguous plate members W₁, W₂ (refer to FIGS. 11, 12).

When the rate h/t of the first inclined face 7 is less than 15%, the gap on the lower side of the first inclined face 7 is narrowed, and the warm wind is difficult to advance to the gap. On the other hand, when the rate h/t exceeds 25%, an amount of the first inclined face 7 projected from an upper edge of the lower side plate member W₂ is reduced, and therefore, the warm wind blown up from the side of the lower side plate member W₂ is made to be difficult to impinge on the first inclined face 7.

Further, when the angle of inclination β of the second inclined face 8 exceeds 20 degrees, although the warm wind is made to be easy to flow to the air gap 9, the warm wind skewedly impinges on the first inclined face 7 of the upper side plate member W₁, and therefore, the force F of lifting up the end portion of the plate member is reduced. On the other hand, when the angle of inclination β is less than 10 degrees, the warm wind is made to be easy to flow in the horizontal direction and the force F of lifting up the end portion of the plate member is reduced.

Further, the best angle γ of intersecting the first and the second inclined faces 7, 8 is 90 degrees. In this case, the warm wind blown up from the side of the lower side plate member W₂ orthogonally impinges on the first inclined face 7 of the upper side plate member W₁ and the force F of lifting up the end portion of the plate member is maximized. However, when a working error is taken into consideration, the angle γ may be 80 through 100 degrees with no hazard practically. When the angle β and the angle γ are determined in this way, the angle of inclination α of the first inclined face 7 becomes 10 through 20 degrees.

Further, although according to the above-described embodiment, the suction pads 3 are arranged in the lattice shape (state of being aligned in both longitudinal and lateral directions) to be adsorbed to the surface of the topmost plate member W₁, depending on the shape of the plate member W, all of the suction pads 3 may not necessarily be arranged to be aligned in both in the longitudinal and in the transverse directions.

Further, although according to the above-described embodiments, the plate member W in a quadrangular shape is used, the shape of the plate member W is not limited thereto.

EXAMPLE

As the plate member W, there is used an aluminum alloy plate having a size of 1000×1700 mm, a thickness of 1 mm coated with a lubricant for pressing. Further, the work is provided with the first and the second inclined faces 7, 8 at an end portion thereof. 15 pieces of the suction pads 3 are arranged to be adsorbed to a surface of the plate member W in vertical 5 rows and horizontal 3 rows at equal intervals of 30 mm. A diameter of the suction pad 3 is 100 mm, and the stroke L of the air cylinder is 30 through 50 mm. The second, the third steps are carried out while blowing out warm wind at 30 through 100° C. from the pipe 4.

In an experiment of 150 sheets of the plate members W, a rate of capable of separating the plate members W completely is 97.3%. Although 2 sheets are taken in remaining 2.7%, the plate members W are separated when the air cylinder 1 reaches an upper dead point at the third step.

As a comparative example, an experiment is carried out with regard to the same plate members W by the same method, in this case, the exfoliating member 53 shown in FIG. 8 is used.

In the experiment with regard to 100 sheets of the plate members W, a rate of capable of completely separating the plate members W is 95%. 2 sheets are taken in remaining 5%, and in 2% thereamong, the plate members W are separated at the upper dead point of the air cylinder 1. 

1. A method of separating a plate member for separating a topmost plate member from laminated plate members, the method comprising: a first step of arranging a plurality of adsorbing devices substantially in a lattice shape to adsorb on a surface of a topmost plate member; a second step of holding the topmost plate member by adsorbing devices arranged in a zigzag shape in the adsorbing devices substantially in the lattice shape, and lifting the topmost plate member by remaining ones of the adsorbing devices; and a third step of lifting the adsorbing devices holding the topmost plate member at the second step.
 2. The method of separating a plate member according to claim 1, wherein, in the second and the third steps, the plate member is lifted by the adsorbing devices by blowing warm wind between the topmost plate member and a second plate member.
 3. The method of separating a plate member according to claim 2, wherein, in advance, a first inclined face continuous to a lower face from an end face of the plate member is formed at a corner portion on a lower side, and a second inclined face continuous to an upper face from the end face of the plate member is formed at a corner portion on an upper side.
 4. A method of separating a plate member for separating a topmost plate member from laminated plate members, the method comprising: a first step of forming a first inclined face continuous to a lower face from an end face of a plate member at a corner portion on a lower side and forming a second inclined face continuous to an upper face from the end face of the plate member at a corner portion on an upper side; a second step of arranging adsorbing devices to adsorbed on a center portion and both end portions of the topmost plate member; a third step of blowing warm wind to the end face of the plate member, holding the topmost plate member by the adsorbing device arranged at the center portion of the plate member, and lifting the topmost plate member by remaining ones of the adsorbing devices; and a fourth step of lifting the adsorbing device holding the topmost plate member at the third step while blowing the warm wind to the end face of the plate member. 